facebook / react · Issue No. 37649

[DevTools Bug]: DevTools v8.0.0 freezes when it can't find sourcemap script resources

Openby mikehdtopened Sep 17, 2026updated Sep 22, 20262 comments

Type: BugStatus: UnconfirmedComponent: Developer Tools

Description

Website or app

(private repo)

Repro steps

I work on a medium size project, and since the release of React Devtools v8.0.0, it freezes up every time I click on any node, it takes forever to try and figure out what the "rendered by" is, causing it to freeze up for long periods. When I'm moving the mouse about in this video I'm trying to click, but you can see it's completely unresponsive until it randomly finishes and hits a different node:

https://github.com/user-attachments/assets/3878148d-268b-4f05-b9a1-4dd375fb1bf4

This is in local dev, React 19.3.0, with Vite as a compiler, if that helps.

The previous DevTools v7.0.1 did not have this performance issue.

How often does this bug happen?

Every time

DevTools package (automated)

No response

DevTools version (automated)

No response

Error message (automated)

No response

Error call stack (automated)

Error component stack (automated)

GitHub query string (automated)

Relay Analysis

View on GitHub

Relay reads this issue against the repository's contribution signals: the files it is likely to touch, how the maintainers triage work this size, and what the first contribution would exercise.

The full analysis for this issue is still being assembled. Until then, the description above and the thread on GitHub are the most reliable context.